There’s a few reasons why you might come across this (use My Oracle Support to find them), but just leaving a quick warning about the ‘/dev/oracleasm/disks’ discovery path. If you have this set, odd things happen to I/O to/from your ASM devices which *may* cause performance degradation and/or other issues. If you haven’t modified SCANORDER/SCANEXCLUDE in particular your disks in /dev/oracleasm/disks will *not* be multipath devices (check the major number of the device to confirm).